


When Derek Changed

by ash_mcj



Category: Teen Wolf (TV)
Genre: Angst, Brielle Stilinski, Emotionally Hurt Derek Hale, F/M, Female Stiles Stilinski, First Love, Peter Hale Tells Stories, Stiles Stilinski Has a Sister, True Mates, Werewolf Mates, Young Derek Hale
Language: English
Status: In-Progress
Published: 2020-10-21
Updated: 2020-10-21
Packaged: 2021-03-08 21:22:04
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,094
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27133105
Author URL: https://archiveofourown.org/users/ash_mcj/pseuds/ash_mcj
Summary: [Peter tells Stiles the story of how his older sister was Derek’s mate]“Well, you know what they say about people who present as emotionless,” Peter said, setting his coffee on the small table in front of him. “They’re the ones who felt the hardest at one point, and couldn’t do it anymore.”“Derek felt the hardest? I think a marker would have more of a capacity for feelings than Derek. Seriously--the only emotions I’ve ever seen him show are anger and annoyance. Both are expressed as glares, growls, and the occasional eye roll.”“Derek wasn’t always like how he is now,” Peter told him, looking with unfocused eyes at one of the walls of the loft as he thought back to a time almost seven years prior. “He was a lot like Scott, actually. A lot like most teenagers. Unbearingly romantic, profoundly narcissistic, tolerable really only to other teenagers.”“So, what happened? What changed him?”“Well, the same thing that changes a lot of young men...a girl.”“You’re telling me a girl broke his little heart and that’s why Derek has the emotional range of a paper clip now?”“I’m saying his heart was so broken that he ripped it out and locked it in a box,” Peter sighed.
Relationships: Derek Hale & Stiles Stilinski, Derek Hale/Original Female Character(s)
Comments: 3
Kudos: 34





	When Derek Changed

**Author's Note:**

> This is just something that popped into my head and I had to write it down really quickly before I forgot it. I hope you guys enjoy!
> 
> *Italicized sections are flashbacks/story parts*

“Derek is avoiding me _again_ , which is pretty frikin’ annoying,” Stiles fumed, pacing back and forth in the living room of Derek’s loft. He had come over three times in the past two days to discuss some werewolf bullshit that he didn’t even want to deal with in the first place--but Derek had managed to not be home all three times. He’d left him what had to be at least fifty messages a day, all left unanswered. “He always does this! If Scott or literally anyone else needs to talk to him, he’s there. I don't get why he hates me so much. I mean, I know I’m annoying, but this is important. I almost cut his arm off when he asked me to--that’s a pretty big favor! He owes me.”

“He doesn’t hate you,” Peter assured him as he brought his cup of morning coffee over to the couch. “You just remind him of things he doesn’t want to be reminded of. Whenever you’re in danger, Derek is the first one trying to figure out how to save your useless human self--believe me. I’d even go as far as to say you’re his favorite.”

“His _favorite?_ He sure has a shit way of showing it.”

“He’s never said anything to me about why he avoids you sometimes, but I assume you make him deal with feelings that he tries his hardest to push down.”

“Derek Hale doesn’t have feelings,” Stiles scoffed, sitting cross-legged on the opposite end of the couch and angling his body to face the werewolf.

“Well, you know what they say about people who present as emotionless,” Peter said, setting his coffee on the small table in front of him. “They’re the ones who felt the hardest at one point, and couldn’t do it anymore.”

“ _Derek_ felt the hardest? I think a marker would have more of a capacity for feelings than Derek. Seriously--the only emotions I’ve ever seen him show are anger and annoyance. Both are expressed as glares, growls, and the occasional eye roll.”

“Derek wasn’t always like how he is now,” Peter told him, looking with unfocused eyes at one of the walls of the loft as he thought back to a time almost seven years prior. “He was a lot like Scott, actually. A lot like most teenagers. Unbearingly romantic, profoundly narcissistic, tolerable really only to other teenagers.”

“Romantic?” Stiles laughed as he fished a piece of mint gum out of his pocket and unwrapped it, before popping it into his mouth. “So, what happened? What changed him?”

“Well, the same thing that changes a lot of young men...a girl.”

“You’re telling me a girl broke his little heart and _that’s_ why Derek has the emotional range of a paper clip now?”

“I’m saying his heart was so broken that he ripped it out and locked it in a box,” Peter sighed. 

“What happened?”

“Do you remember Derek before he was an alpha?” Peter asked him, turning his body towards the teenager and smiling in anticipation for the story he decided to tell. “He had blue eyes, if you recall. Do you know why some wolves have blue eyes?”

“I always thought it was, like, a genetic thing.” Stiles shrugged, thrown off by the conversation’s different direction. “What does this have to do with Derek being a romantic teenager?”

“It’s not genetic--all betas start with yellow eyes. If you want to know what changed Derek, you need to know what changed the color of his eyes.”

“Okay then, Uncle Peter, tell me a story,” Stiles said with mock enthusiasm.

“Derek was in his sophomore year of high school…” Peter began.

_“Mr. Hale, I think you would benefit from some space away from your friends. Why don’t you find a new seat?” Mr. Suaste prompted, motioning with his hands for Derek to stand and relocate._

_Derek rolled his eyes and grabbed his backpack from the floor, before walking over to the nearest empty seat, which happened to be beside a girl with short brown hair, pale skin, and amber eyes._

_"Hey, I’m Derek,” He whispered to her as he leaned slightly in her direction._

_“Hey; I didn’t ask.” She shot back with a playful smirk, before looking him over thoughtfully. “Why’d you come to my table? There are three completely empty desks in this classroom.”_

_“I saw a hot girl sitting all alone and couldn’t help myself,” Derek answered with a smile. In truth, he hadn’t seen the empty desks that were, as she pointed out, only a few feet away._

_“Beautiful would get you further,” She told him._

_“What?”_

_“For the next time you use that pickup line, or one similar. You should use beautiful, instead of hot. It gives the illusion that you might have more innocent intentions, instead of just trying to get laid.”_

_"Noted.”_

_“You're welcome.”_ _The girl turned her eyes away from Derek and looked to the front of the classroom, where the teacher was reading from a PowerPoint._

_“What’s your name?” Derek asked._

_“Wouldn’t you like to know?” She teased._

_“Mr. Hale, would you please tell the class what the backbone of DNA is, from your reading last night?” Mr. Suaste called out, causing Derek to wince._

_“It’s, uh…” He trailed, scrambling to find something to say, even though he had no idea that DNA even_ had _a backbone._

_“Alternating sugar and phosphate groups,” She whispered, to his relief._

_“Alternating sugar and phosphate groups, Mr. Suaste,” He said confidently, praying that the girl knew what she was talking about._

_“That’s right...good choice picking Miss Stilinski to sit next to.”_

_“Stilinski, huh?” Derek asked, looking back at her as their teacher returned to his lecture._

_“Brielle,” She corrected, holding out her hand._

“Wait,” Stiles said, looking confusedly at Peter. He felt his chest tighten at the name that fell off the older man’s lips and he shook his head to clear his thoughts. “Derek knew my sister? That’s what I remind him of?”

“You two are remarkably similar, you know,” Peter commented. “Not even just the appearance, but the snarkiness, the intelligence...it’s uncanny.”

“Yeah, I’ve been told,” Stiles said, scratching the back of his neck uncomfortably. “So, Derek ignores me because I remind him of Brielle and she’s...y’know, dead.”

“It’s not as simple as that,” Peter told him, annoyance laced in his tone. “Are you going to stop talking and let me continue the story?”

“Yeah.”

“Once they met, they could hardly spend any time apart. There was lots of playful banter that quickly turned into passionate making out and groping in any dark corner they could find.”

“ _Please_ skip this part,” Stiles stopped him, nose scrunching up in disgust. 

“Alright, alright,” Peter said, holding his hands up in surrender. “They were fifteen years old, just a year younger than you are now, and full of more affection and excitement than either of them knew they could feel. They fell in love. First loves are special, but theirs was even more so, because Derek quickly realized that Brielle was his mate.”

_“Peter,” Derek hissed as he approached him on the front lawn of the Hale house. He grabbed his arm and pulled him towards the woods, which he always did when he wanted privacy. A house full of werewolves wasn’t the best place to hold private conversations that you didn’t want others to hear._

_“What’s wrong?”_

_“I have a...problem. Well, not a problem. It’s just...it’s Brielle,” Derek said, once they were far enough away from the house._

_“Brielle is a problem? I thought you loved her or something?”_

_“I do. She’s not the problem,” Derek clarified, before looking around and running his hand through his hair several times. “Okay, so we were...doing things...today and I felt something...something I hadn’t really felt as strong before, and I--”_

_“Derek, as long as you use condoms, it’s not a big deal,” Peter laughed, clapping him supportively on the shoulder. Derek looked scandalized for a moment, before shaking his head._

_“That’s_ not _what I’m trying to tell you.”_

 _“Well, what_ are _you trying to tell me? Do you even know?”_

 _“No! Yes. But--ugh!” Derek groaned and put his face in his hands, before saying, “I felt a pull. Like a strong bond--like a_ pack _bond, but...different. Brighter. Warmer. I think it was a mate bond. I remember my mom telling me about them and how they become finalized when you..._ do it _...and honestly, I totally forgot about the conversation until today. But then we did it for the first time and that happened and...what does that mean? For us. She doesn’t even know I’m a werewolf, and now I’m mated to her!”_

_“You’re sure?” Peter asked, eyebrows furrowing as the information sunk in. “That...that’s really rare. I don’t even know anyone who’s found a mate. It almost never happens.”_

_“I know...but yeah, I’m sure. I can_ feel _her, Peter. It’s so much stronger than a pack bond or anything I’ve ever felt...I can feel her emotions. For example, she’s happy right now...kinda hungry. I can feel it as if it’s my own feelings, but just...displaced.”_

_“Derek, this is...it’s amazing,” Peter said with a smile. “But...what are you going to do when she finds out? Bad things always happen to humans who run with wolves--you know that.”_

_“She doesn’t need to know. Not yet.”_

_“She’ll find out, though--they always do,” Peter told him. “If she hasn’t already...Brielle is exceedingly smart. I wouldn’t be surprised if she already knew, but doesn’t want to bring it up.”_

_“Either way...it doesn’t matter.”_

_“It does, though. You know it does. You know what you’ll have to do, if you want to keep her around.”_

_“Peter...I…” Derek struggled, looking down at his hands._

_“Derek,” Peter said softly. “There’s a window of opportunity, you know. If she really matters that much to you...Ennis needs a packmate. He would do it, if you asked.”_

“You wanted Derek to get _Ennis_ to bite my sister?" Stiles growled, glaring at Peter. "Ennis, the extremely aggressive and scary alpha?”

“Why not Ennis? At the time, he needed a new member for his pack because the hunters put an arrow through the throat of his beta, and Brielle was young and strong. Plus, doing a favor for Derek meant Ennis would be in good with Talia. Back then, everybody wanted to be in good with her.”

“That wasn’t you or Derek’s choice to make.”

“I know, but once that seed was planted...Derek just couldn’t get it out of his head. The opportunity to have his mate with him forever was fleeting fast and he couldn’t sleep or eat without wanting to call up Ennis.”

“I highly doubt it was just one seed, Peter...you like ruining people’s lives.”

“First of all, the bite is a _gift_. It doesn’t ruin lives--it enhances them. Speed, reflexes, senses, everything,” Peter defended, before looking away with a look that Stiles almost thought resembled shame, if Peter was capable of feeling such a thing. “Well, most of the time.”

“When you offered me the bite...you said I would turn into a werewolf, if it didn’t kill me,” Stiles whispered, realization flashing across his pained features as he pieced things together. “It...it rejected, didn’t it? Ennis bit her and it rejected?”

“It did,” Peter confirmed. “Derek carried her to the bunker under the Nemeton, which we used to frequent a lot when we were younger.”

“Were you there? When she died?”

“I was.” Peter nodded. “Not in plain sight. I gave them their space, but I was there. Someone needed to take care of the body once she died. Now, I’m not a remorseful kind of person...but seeing it...I knew I shouldn’t have planted the seed in Derek’s head. I knew I should have stopped it. I don’t pretend to be a good person or a good uncle, but I’ve never seen something like that and if anyone wants to call me a villain, it’s because of my part in your sister's death.”

_Derek was seated on the dirt floor underneath the Nemeton, holding Brielle in his lap. Her head was rested on his shoulder and their hands were clasped together as Derek took all the pain from her that he could. Black blood was dripping from the downturned corners of her mouth and dribbling down her chin, and her hair was clinging to her forehead with sweat._

_“I’m sorry,” Derek whispered into her hair as he held her against him. Tears were forming in his eyes while he took in her scent for what he knew would be the last time._

_“I knew,” Brielle said softly, tilting her head up to look at him._

_"What do you mean?”_

_“I’ve seen things in this town before...things no one could explain. I’ve always known there was something different about Beacon Hills...and then you sat by me in science and...the way that you talk--how you’d say things, like you’d catch a scent. Or how you’d hear things no one else can. You’re really shit at keeping it under wraps, wolf boy.”_

_Brielle smirked at him, before wincing and letting out a choked sound as she squeezed Derek’s hand. Derek clutched hers in return and shut his eyes, letting out a groan as he absorbed more of her pain. Brielle relaxed in his arms again and he pressed a kiss to her sticky forehead._

_“And you still liked me?” Derek asked in disbelief._

_“I loved you, Der,” She corrected him with a smile. She reached up and caressed the side of his face affectionately, before letting out a shaky breath. “I’m gonna die, aren’t I?”_

_"Yeah,” Derek admitted, the held-back tears finally spilling over his cheeks and dripping down onto their interlocked hands._

_They laid there in silence for a few more minutes, holding each other, before Brielle let out a strangled cry and fisted her hand into the front of his shirt. “Derek...I can’t...I can’t take it anymore. If I’m gonna die, there’s no point in...in waiting.”_

_"Brie, I can’t.” Derek shook his head weakly. He knew how much pain she was in. Not only by the way her breaths were coming in ragged or how her whimpers were ringing in his ears--or even by the pain he had been taking from her. He could_ feel _it. His mate bond felt like a dagger through his chest and he could barely breathe through it._

 _“Please, Derek,_ please _” She begged, rubbing her blood-covered thumb over the back of his hand soothingly._

_“I’m so sorry,” He cried, touching their foreheads together._

_“I’m not. I’ve had the best year of my life...and I get to die in the arms of my first and only love. I’m not sorry at all.” She assured him. “But please...I can’t do this anymore. Please just make it stop.”_

_Derek pulled back slightly and repositioned Brielle into a proper hug position that allowed him to get a better hold around her torso. “I love you.”_

_“I love you, too," Brielle told him. She wrapped her hands around his bicep and placed a kiss against his shoulder._

_Derek took a deep breath and his eyes turned a bright gold, before he squeezed her tightly and heard the_ snap _of her spine that was only drowned out by the agonizing roar that the fifteen year old boy let out as Brielle fell limp against him._

Stiles looked away, choosing to focus on the laces of his sneaker instead of the man talking. His vision blurred, before a tear slid down his cheek and he took a steadying breath. Hearing about his older sister's last moments caused his stomach to churn and his chest to hurt. She was a part of this supernatural world he found himself in before he was even out of elementary school, and he never knew. As much as it pained him to hear about her, he also felt an odd sense of peace with it that he hadn't felt before. He thought she had died alone in the woods after being attacked by a wild animal--because that was the story that went around town and the one in the police report--but she wasn’t alone. It was odd to feel grateful towards the grumpy guy that he had just found out killed his sister, but he was. 

On top of that, Stiles was realizing what Derek had really been through. Derek was fifteen years old when he went through things Stiles couldn't even imagine. He thought that dealing with a rampaging alpha and a kanima at fifteen was a lot, but he hadn’t lost anybody that mattered to him. Derek had fallen in love, found his _mate_ , and then had to kill her. Then, a year later, his house was burned down with most of his family inside. Derek had lost everything in his life.

“I remember taking her from his arms,” Peter continued. “To the woods...to a place where I knew it would be found. Another tragedy in a long line of Beacon Hills animal attacks.”

“So...the blue eyes?” Stiles prompted, subtly wiping his face with the sleeve of his flannel and leaning back into the couch cushions.

“Taking an innocent life takes something from you, as well. A bit of your soul... _darkening_ it. Dimming the once brilliant, golden yellow to a cold, steel blue. Like mine,” Peter revealed, flashing his eyes.

"They're blue because of Brielle?"

“Yeah. Derek lost so much that he just...turned it off. Or, I assume that’s how it went. He doesn’t tell me anything anymore.” Peter shrugged, before reaching out to grab his coffee again from the table. “It’s easier to keep everyone at arm’s length, rather than risk getting attached to them, just to lose them. Everyone Derek has loved has died, so I figure he thinks there’s no point in risking it anymore. He’d rather give up the option at finding any semblance of happiness or love again, to prevent the possibility of being broken any more--because that would really do him in. Not that there’s any point of trying to move on for him, anyway. Wolves mate for life...when one side of the mate bond dies, the other somewhat dies, too. Even if Derek hadn’t been the one to kill her, he would never have been himself again."

**Author's Note:**

> Is anyone else crying with me? No? Just me? Cool.
> 
> Hope you guys liked this! Kudos/Comments appreciated!


End file.
